add unix makefiles for docshell r=mcafee,paulmac. also changed IDL to C++ in the two .cpp files' emacs comments and added a newline at the end of them (files not built by default)

docshell/build/nsDocShellModule.cpp

@@ -1,4 +1,4 @@
-/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
  *
  * The contents of this file are subject to the Mozilla Public
  * License Version 1.1 (the "License"); you may not use this file
@@ -82,4 +82,4 @@ NSUnregisterSelf(nsISupports* aServMgr, const char* aPath)
 	NS_ENSURE_SUCCESS(rv, rv);
 
 	return rv;
-}
+}